Causes of Pituitary Tumors

Receiving a diagnosis of pituitary tumor can be challenging. Patients are often left with questions about why this happened and if they could have done anything to prevent it from occurring. They also worry if their children or family members could be at risk of such tumors. In this article, we will review the causes of pituitary tumor formation.

The formation of pituitary tumors is like the development of tumors in general, as it can be attributed to random changes (mutations) in the DNA of cells in the pituitary gland that promote continued growth. As we age, cells normally replicate and divide to support the demands of daily life and replace old or damaged cells. During this process of cellular division, cells must replicate the entire length of their DNA and pass this along to the newly created cell.

Cellular replication is a phenomenal feat, as it requires the copying of billions of units of genetic information. Although this is done quite accurately, mistakes can happen. If these mistakes occur in genes involved in regulating growth, this may result in uncontrolled division and cause the formation of a tumor.

While most mutations are random, there are some rare instances when gene mutations can be passed down from parents to their children. As a result, people can inherit a preexisting genetic mutation that significantly increases their risk for developing pituitary tumors.

Familial inheritance of genetic mutations predisposing someone to pituitary tumors may be part of a broader syndrome that results in the formation of tumors in other parts of the body. These syndromes include multiple endocrine neoplasia syndrome (MEN) type I and IV, McCune-Albright syndrome, or Carney complex. All these syndromes are exceptionally rare.

While it is true that the pituitary gland is an important regulator of stress hormones, pituitary tumors occur as the result of genetic mutations. There is no evidence implicating stress in the development of genetic mutations in the pituitary gland. Therefore, stress cannot be considered among causes of pituitary tumors.

Pituitary tumors occur because of genetic mutations in DNA leading to uncontrolled growth of pituitary cells. There is no specific hormone that predisposes or causes the formation of pituitary tumors. Because the pituitary gland is responsible for secreting many different hormones, pituitary tumors may also release hormones and cause abnormal hormone levels. Hormone abnormalities are thus a consequence and a sign of a pituitary tumor, not a cause.

The risk of developing many types of tumors can be reduced with certain lifestyle modifications such as losing weight or quitting smoking. However, pituitary tumors have not been linked to any environmental exposures or risk factors. As a result, there is no known way to prevent pituitary tumors from forming. In fact, as many as 10-20% of people may develop pituitary tumors during their lifetime. A majority of these do not cause symptoms and thus either go undiscovered or do not require any type of treatment.

Patients often ask what can cause a pituitary tumor and if there is anything they could have done to prevent it. Pituitary tumors occur as the result of random genetic mutations, and there are no known risk factors that can be avoided.

• Pituitary tumors occur because of random genetic mutations.
• There are no known lifestyle risk factors or environmental exposures that increase the risk of developing pituitary tumors.
• There is no known way to prevent the development of pituitary tumors.

• Pituitary Network Association 
• National Brain Tumor Society
• American Brain Tumor Association 
• Pediatric Brain Tumor Foundation
• Endocrine Society 
• Pituitary Foundation 
• Cushing’s Support & Research Foundation